Mechanical dialyzer



Oct. 26, 1954 A. HENLEY 2,692,854 MECHANICAL DIALYZERS Filed Jan. 8, 1951 2 Sheets-Sheet 1 m H Ll...

INVENTOR. ALFRED HENLEY #V/MW 1% A 1' ee NE Y Oct. 1954 A. HENLEY 2,692,854

MECHANICAL DIALYZERS Filed Jan. 8, 1951 2 Sheets-Sheet 2 INVENTOR. A LFR ED HENI. EY'

, /MZM A TTORNE Y Patented Oct. 26, 1954 MECHANICAL DIALYZER Alfred Henley, Takoma Park, Md., assignor to American Instrument Spring, Md.

Company, Inc., Silver Application January 8, 1951, Serial No. 204,984

11 Claims. 1

'This invention relates to biological laboratory equipment, and more particularly to apparatus for the dialysis of protein and other solutions.

A-main object of the invention isto provide a novel and improved apparatus for dialyzing protein-and other solutions, such asbloodserum or-the like, said apparatus being simple in construction, being easy to manipulate, and greatly reducing the time required for dialysis, as over previously known apparatus.

Afurther object of the invention is to provide an improved mechanical dialyzing apparatus for use in equilibrating protein or other solutions against a suitablebuffer mixture prior to study *of the solutionin electrophoresis 'or similar apparatus, the improved dialyzingapparatus involving relatively inexpensive parts, being sturdy in "construction, andbeing compactin size.

A still further object of the invention isto provide-animproved mechanical dialyzer for use in preparing protein and other solutions for study in electrophoresis or similar apparatus, said dialyzer providing reduction of the time required for equilibration of the solution under study to a minimum, employing very simple components, being readily assembled, and requiring a minimum degree'of manufacturing precision in fabricating the various parts thereof.

Further objects and-advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein:

Figure l-isavertical cross-sectional view taken "through an improved mechanical dialyzer constructed in accordance with the present invention.

Figure 2 is a top plan view of the mechanical Idialyzer of Figure 1.

Figure -3 is an enlarged fragmentary crosssectional detail view taken on line 3-3 of Fig .ure 1.

Figure 4 is afragmentary cross-sectional detail view taken on line 4-4 of Figure 3.

Figure dis a fragmentary vertical cross-sectional view taken through a modified form of mechanical dialyzer according to the present invention, said view being taken on line 5-5 of Figure 6.

Figure 6 is a top plan view of the mechanical I dialyzer of Figure 5.

taining proteins as well as low-molecular, diffusible ions and organic compounds must be collar member. reduced lower portion I8, and frictionally ening at low temperature and for a considerable period of time. For example, 'in electrophoresis experiments on normal and pathological human blood serum and plasma, where static dialysis at 0 to 2 centigrade has been employed, the'process has required three days, the outside buffer solution being changed every day. An alternative procedure "has been to rotate 'the buffer solution for one hour at room temperature, replacing it by fresh buffer, and allowing dialysis to proceed for 24 hours or more at 0 to 2 centigrade.

For a furtherdiscussion of the electrophoresis apparatus and method, referenceis made to-U. S. Patent 2,495,297 to Kurt G. Stern, issued January 24, 1950. In said patent'an example of the above dialysis process, as a preliminary step in performing an electrophoresis experiment, is fully described.

In clinical work, the time required for the equilibration process represents a factor of major importance, since it delays appreciably the examination of the serum or plasma in the electrophoresis apparatus, and hence the availability of the results to the medical personnel involved.

A main purpose of the present invention is therefore to provide an apparatus wherein the time course of dialysis may be reduced to aminimum compatible with the requirements of precise electrophoresis experiments.

Referringnow tothe drawings, and more particularly to -Figures l to 4, the mechanical dialyzing apparatus may comprise a glass receptacle II provided with a removable, peripherally flanged top cover I2. Secured on the top cover I2 is a stirrer motor I3 whose shaft I4 extends rotatably through the center of the cover f2.

Shaft I 4 is formed with a depending axialstud I 5 to which is secured a collar member I6, as by a set screw II provided in the upper portion of said As shown, the collar it has a gaged on said reduced lower portion is a sleeve I9 of rubber or similar elastic deformable material. Frictionally secured in the lower portion of sleeve H! is the shaft 20 of a helically twisted stirrer rod 2|.

Secured to the under surface of cover |2 coaxially with the shaft I4 is a depending, downwardly tapering, rigid conical shell member 22, which extends a short distance below the end of sleeve I9 and which is open at its lower end. The inside diameter of said lower end is substantially greater than the outside diameter of the sleeve l9, whereby the sleeve member is free to flex to a substantial degree inside said shell member, as when the stirrer rod 2| deviates from a vertical position.

The shell member 22 is formed at the lower portion of its outer surface with an annular groove 23. Designated at 24 is the dialyzing membrane, which is in the form of a bag of suitable, thin, semi-permeable material, such as cellophane, or the like. A typical material may be Visking sausage casing. The upper portion of the bag 24 is engaged over the lower end of the shell member 22, as shown, and is sealingly clamped thereto by a rubber ring 25 arranged to force an an- 7 nular portion of the bag 24 into groove 23.

It will be noted that in order to secure the bag to the shell member, it is merely necessary to engage the bag on the lower portion of the shell member and then roll the ring 25 upwardly along the bag until the ring slips into the annular groove 23, the ring being stretched by the upwardly flaring configuration of the shell member and hence exerting a tight sealing and clamping action on the bag in cooperation with the groove 23. It will be further noted that the bag may be readily detached from the shell member 22 by exerting downward force on the ring 25, whereby said ring is disengaged from the groove 23.

Designated at 26 is a relatively heavy, rigid ring or collar, which is disposed in the bottom of the bag 24. Ring 26 performs a double function:

it prevents the lower portion of the bag from collapsing and it weights the bag so that it remains relatively stationary while the stirrer rod 2| is revolving and oscillating.

In operation, the liquid to be dialyzed is placed in the bag 24 and thebagis secured to the shell member 22 as above described. The buffer solu-- tion is placed in the receptacle II and the cover |2 is then placed on the top rim of said receptacle. The motor |3 drives the shaft Id at a relatively slow speed, suitable speed-reducing means being incorporated in said motor. Torque is transmitted to the helical stirrer rod 2| through the flexible sleeve l9. Due to the yieldability of the connecting sleeve IS, the stirrer 2| revolves the liquid in bag 24 gently in the bag and at a relatively slow rate. The reaction of the liquid causes the stirrer to be deviated from a vertical position instead of producing turbulence in the liquid. Since turbulence is minimized, dialysis is allowed to proceed substantially under the same external physical conditions prevailing if the liquid in the bag were stationary relative to the inside surface of the bag, but :the rate of dialysis is greatly accelerated since many more molecules or ions in the liquid are brought into contact with the semi-permeable membrane of the bag in a given period of time than if the natural movements of said molecules or ions were alone relied on for dialysis.

Secured to the top cover l2 are a pair of upstanding support legs 21, 21 whose top ends are flush with the top surface of motor l3 and which are spaced so as to define tripod elements in conjunction with the motor for supporting the cover in an inverted horizontal position when the cover is removed from the receptacle In the modified form of the invention shown in Figures 5, 6 and '7, the bag 24 is sealingly clamped to the depending conical shell member, shown at 22, by a rigid clamping ring 28, which is provided with diametrically opposed apertured lug portions '29, 29. The upstanding tripod legs, shown at 21', 21 are arranged diametrically opposite each other with respect to the motor shaft l4. The lower portions of legs 21, 21' comprise depending threaded stud elements 30, 30 which extend through cover I2 and are secured thereto by nuts 3|, 3|. The stud elements 30, 30 extend through the respective apertured lug portions 29, 29 and are provided below said lug portions with knurled nuts 32, 32 which exert upward force on the ring member 28, and cause said ring member to sealingly clamp the rim portion of bag 24 to the shell member 22.

In the arrangement of Figures 5, 6 and 7, it is not necessary to provide an annular groove in the external surface of the shell member, and the size of the aperture in the ring member 28 is not critical, since the tapering configuration of the shell member provides clamping engagement of the ring member therewith regardless of variations in size of said aperture.

Although certain specific embodiments of improved mechanical dialyzers have been disclosed in the foregoing description, it will be understood that various modifications within the spirit of the invention may occur to those skilled in the art. Therefore it is intended that no limitations be placed on the invention except as defined by the scope of th appended claims.

What is claimed is:

1.. A mechanical dialyzer comprising a receptacle, a top cover removably mounted on said receptacle, a motor mounted on said cover, a depending shaft element coupled to said motor and extending through said cover, a depending stirrer, elastic deformable means resiliently connecting said stirrer to said shaft element, and a bag of permeable membrane material secured to said cover around said stirrer.

2. A mechanical dialyzer comprising a closed receptacle, a vertical shaft element extending rotatably through the top wall of the receptacle, a stirrer rod, elastic deformable means resiliently connecting said stirrer rod to said shaft element, and a bag of permeable membrane material secured to said top wall around said stirrer rod.

3. A mechanical dialyzer comprising a closed receptacle, a vertical shaft element extending rotatably through the top wall of the receptacle, an annular shell depending from said top wall around the shaft element, a depending stirrer rod, elastic deformable means resiliently connecting said stirrer rod to said shaft element inside said shell, said stirrer rod depending through the bottom rim of said shell, and a depending bag of permeable membrane material secured to said shell and surrounding said stirrer rod.

4:. A mechanical dialyzer comprising a closed receptacle, a vertical shaft element extending rotatably through the top wall of the receptacle, a rigid annular shell depending from said top wall around the shaft element, a depending sleeve member of elastic deformable material secured to said shaft element, a depending stirrer rod secured to said sleeve member, whereby the stirrer rod is resiliently connected to said shaft element, said stirrer rod depending through the bottom rim of said shell, and a depending bag of permeable membrane material secured to said shell and surrounding said stirrer rod.

5. A mechanical dialyzer comprising a closed receptacle, a vertical shaft element extending rotatably through the top wall of the receptacle, a rigid annular shell depending from said top wall around the shaft element, a depending sleeve member of elastic deformable material secured to said shaft element, a depending stirrer rod secured to said sleeve member, whereby the stirrer rod is resiliently connected to said shaft element, said stirrer rod depending through the bottom rim of said shell, a depending bag of permeable membrane material secured to said shell and surrounding said stirrer rod, and a rigid, relatively heavy spreader member the bottom of said bag.

6. A mechanical dialyzer comprising a closed receptacle, a vertical shaft element extending rohorizontally disposed in tatably through the top wall of the receptacle, a

stirrer rod, elastic deformable means resiliently connecting said stirrer rod to said shaft element, a bag of permeable membrane material secured to said top wall around said stirrer rod, and a rigid, relatively heavy spreader member horizontally disposed in the bottom of said bag.

7. A mechanical dialyzer comprising a closed receptacle, a vertical shaft element extending rotatably through the top wall of the receptacle, a rigid, downwardly tapering, annular shell depending from said top wall around the shaft element, the outer surface of said shell being formed with a peripheral groove, a depending stirrer rod, elastic deformable means resiliently connecting said stirrer rod to said shaft element, said stirrer rod depending through the bottom rim of said shell, a depending bag of permeable membrane material engaged on the shell and surrounding the stirrer rod, and a securing ring of elastic material engaged over the upper portion of the bag adjacent the groove in said shell and urging said portion into the groove, whereby the bag is clamped to the shell.

8. -A mechanical dialyzer comprising a closed receptacle, a vertical shaft element extending rotatably through the top wall of the receptacle, a rigid, downwardly tapering, annular shell depending from said top wall around the shaft element, the outer surface of said shell being formed with a peripheral groove, a depending stirrer rod, elastic deformable means resiliently connecting said stirrer rod to said shaft element inside said shell, said stirrer rod depending through the bottom rim of said shell, a depending bag of permeable membrane material engaged on the shell and surrounding the stirrer rod, and a securing ring of elastic material engaged over the upper portion of the bag adjacent the groove in said shell and urging said portion into the groove, whereby the bag is clamped to the shell.

" aged on the 9. A mechanical dialyzer comprising a closed receptacle, a vertical shaft element extending rotatably through the top wall of the receptacle, a rigid, downwardly tapering, annular shell depending from said top wall around the shaft element, a depending stirrer rod, elastic deformable means resiliently connecting said stirrer rod to said shaft element, said stirrer rod extending through the bottom rim of said shell, a depending bag of permeable membrane material engaged on the shell and surrounding the stirrer rod, a rigid clamping ring engaged over the upper portion of the bag around said shell, and means connecting said clamping ring to said top wall and arranged to exert upward force on said clamping ring, whereby the bag is sealingly locked to the shell.

10. A mechanical dialyzer comprising a closed receptacle, a vertical shaft element extending rotatably through the top wall of the receptacle, a rigid, downwardly tapering, annular shell depending from said top wall around the shaft element, a depending stirrer rod extending through the bottom rim of said shell, elastic deformable means resiliently connecting said stirrer rod to said shaft element, a depending bag of permeable membrane material engaged on the shell and surrounding the stirrer rod, a rigid clamping ring engaged over the upper portion of the bag around said shell, and means connecting said clamping ring to said top wall and arranged to exert upward force on said clamping ring, whereby the bag is sealingly locked to the shell.

11. A mechanical dialyzer comprising a closed receptacle, 2, vertical shaft element extending rotatably through the top wall of the receptacle, a rigid, downwardly tapering, annular shell depending from said top wall around the shaft element, the outer surface of said shell being formed with a peripheral groove, a depending stirrer rod extending through the bottom rim of said shell, elastic deformable means resiliently connecting said stirrer rod to the shaft element, a depending bag of permeable membrane .material enshell and surrounding the stirrer rod, and a securing ring of elastic material engaged over the upper portion of the bag adjacent the groove in said shell and urging said portion into the groove, whereby the bag is clamped to the shell.

References Cited in the file of this patent UNITED STATES PATENTS 

1. A MECHANICAL DIALYZER COMPRISING A RECEPTACLE, A TOP COVER REMOVABLY MOUNTED ON SAID RECEPTACLE, A MOTOR MOUNTED ON SAID COVER, A DEPENDING SHAFT ELEMENT COUPLED TO SAID MOTOR AND EXTENDING THROUGH SAID COVER, A DEPENDING STIR- 